In a display device, as shown in FIG. 1, generally there is provided only one display screen. This kind of display device can only realize a single-sided display and thus more and more cannot meet the requirement of the service businesses such as communication, government agencies, banking, traffic management, and so on.
In order to accommodate the development of the above industries, a display device capable of achieving double-sided display or illumination has been developed. As shown in FIG. 2, this kind of display device can achieve double-sided display.